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.Dd November 11, 2014 .Dt CPU_ROOTCONF 9 .Os .Sh NAME .Nm cpu_rootconf , .Nm rootconf , .Nm setroot .Nd root file system setup .Sh SYNOPSIS n sys/types.h n sys/systm.h .Ft void .Fn cpu_rootconf "void" .Ft void .Fn rootconf "void" .Ft void .Fn setroot "device_t bootdv" "int bootpartition" .Sh DESCRIPTION The .Fn cpu_rootconf is a machine-dependent interface invoked during system bootstrap to determine the root file system device and initialize machine-dependent file system state. .Fn cpu_rootconf provides the global variables .Fa booted_device , .Fa booted_partition , .Fa booted_startblk , .Fa booted_nblks , and .Fa bootspec . .Fa cpu_rootconf invokes the machine-independent function .Fa rootconf which calls the function .Fa setroot to record the root device and the root partition information for use in machine-independent code.
p .Fa rootconf may adjust the global variables and determines the parameters for setroot. This is for example used to translate a device and partition number provided by the bootloader into a disk wedge device covering the same partition.
p If the bootloader already identified a disk wedge, it passes a non-zero value for .Fa booted_nblks , then .Fa booted_startblk and .Fa booted_nblks specify a disk wedge as the boot device.
p .Fa setroot evaluates several sources to identify the root device in the following order until a valid device is selected: l -enum t The kernel configuration variable .Fa rootspec which is set by .Xr config 1 . The value is the name and unit of the root device, e.g., "sd0" (disk) or "dk0" (wedge) or "le0" (network) or the prefix "wedge:" followed by the name of the disk wedge. For disk devices the partition passed as argument to .Fa setroot is used. t The variable .Fa bootspec following the same syntax. t The result of an interactive query of the root device if .Fa boothowto has set the flag .Dv RB_ASKNAME . The input uses the same syntax as the previous sources. Here also the kernel dump device is queried. t The boot device and partition passed as arguments. .El
p If a root device cannot be selected, .Fa setroot sets the .Dv RB_ASKNAME flag and loops.
p Otherwise the kernel dump device is identified in a similar manner from l -enum t The result of a previous interactive query. See above. t The kernel configuration variable .Fa dumpspec , if set. t The second partition of the root device, if it is a regular disk. t The first disk wedge device of type DKW_PTYPE_SWAP. .El .Sh SEE ALSO .Xr config 1 , .Xr dk 4 , .Xr boot 8 , .Xr boothowto 9
Indexes created Tue Sep 23 02:09:52 GMT 2025